Skin tests are important in children with β-lactam hypersensitivity, but may be reduced in number

Background: There is no perfect agreement on how to perform an allergy workup in suspected beta-lactam (BL)–allergic children, since skin test (ST)–induced pain is often a limitation. The aim of the study was to assess the possibility of reducing the number of ST in children when performing a complete allergy workup for BL hypersensitivity reactions. Methods: A retrospective analysis of all patients referring to the Allergy Unit of the University Hospital of Montpellier (France) with positive responses in immediateand non–immediate-reading ST to a BL over a 16-year period was performed, to determine the positive predictive value (PPV) of ST. All pediatric patients with a suspected BL hypersensitivity were skin-tested with the suspected drug only, during the following 54 months. Results: A total of 319 patients reporting 328 BL reactions were included in the retrospective study. The PPV of ST for the reported drug was of 99.4%. Based on the results, the number of patients to include in the prospective study was estimated to be 101. In the prospective study, 229 children were included. We diagnosed a BL hypersensitivity in 12 children (5.2%): Diagnosis was reached in 6 (50.0%) through ST (delayed reading for all) and in 6 through drug provocation test (DPT). Conclusion: ST with BL should therefore be performed as a screening test, before DPT, and testing only the suspected drug may be sufficient when dealing with children.